Colorado Snow Day Calculator
From March blizzards on the Front Range to whiteouts on the Eastern Plains, Colorado snow can land in almost any month. Check your chances now.
Why Colorado gets so many snow days
Colorado does winter at altitude: Denver sits about 1,610 metres above sea level and most Front Range schools are higher still, so storms that would be rain elsewhere fall as snow here. Denver averages roughly 1.4 metres of snow a season on the long National Weather Service record, and — unusually — its snowiest month is March, at about 29 cm, with April close behind. Snow is possible from September to May — and spring is peak snow-day season: the March 2003 blizzard dropped about 81 cm on Denver in three days.
How Colorado districts decide
- Superintendents typically start checking forecasts, road crews and neighbouring districts before dawn when a storm is expected overnight — Denver Public Schools aims to decide by about 5 AM.
- What matters most is the 4–7 AM window: can buses run safely, can plows keep up, and will conditions improve or worsen by dismissal?
- Most districts weigh snowfall rate, ice, wind and visibility — an upslope storm can bury the Palmer Divide or the foothills while Denver gets far less.
- There is no statewide snowfall threshold in Colorado. Each superintendent makes the call for their own district, which is why Douglas County can close while Denver stays open, or the other way round.
Colorado snow day tips
Enter your ZIP code above and pick your school type for your most honest score — rural districts, with longer bus routes, typically close more readily, while colleges are the least likely to cancel. Our score runs from 0–95% and weights that critical 4–7 AM window most heavily, alongside a separate storm risk score and hourly detail showing when conditions peak. To understand the method behind the number, read how the calculator works before the next storm. Check again early in the morning — upslope flow can strengthen overnight and double what your part of the metro receives. Our snow day predictor on the homepage covers any US or Canadian code, mountain town or Front Range suburb alike.
Upslope storms and spring blizzards, explained
Colorado's signature Front Range snow comes from upslope flow. When a low-pressure system sits to the southeast and winds turn easterly, moist air pushes westward against the rising foothills and the Palmer Divide. Forced up, the air cools and its moisture wrings out as heavy snow on the metro side of the range — while the high mountains stay comparatively quiet. Elevation does the rest: totals climb sharply over short distances, from Denver at about 1,610 metres to the Palmer Divide at up to about 2,400 metres. And because spring air holds more moisture, March and April upslope storms are often the year's heaviest — wet, branch-snapping snow, not light midwinter powder.
Three Colorados in winter
- The Front Range metro — Denver, Boulder and the suburbs: Denver Public Schools, the state's largest district with about 89,000 students, decides alongside Jeffco Public Schools, Cherry Creek, Aurora and Boulder Valley. Boulder averages about 2.4 metres of snow a season on the NOAA 1991–2020 normals — far more than Denver — and Douglas County districts on the Palmer Divide often close when Denver stays open.
- The high mountains and ski country: Breckenridge's town station averages about 4.7 metres of snow a season (1991–2020), and ski areas above town record much more. Yet schools there typically stay open through storms that would shut the metro — everyone is built for snow, so closures are rare.
- The Eastern Plains: On the plains, wind matters more than the snow total. Blizzards can erase visibility, drift rural roads shut and close highways such as I-70 east of Denver, so rural districts with long bus routes often close on wind and visibility alone.
Cold days: closures with no snow at all
Some Colorado closures happen under clear skies. Arctic outbreaks pool against the Front Range, and when the cold arrives with wind — especially on the Eastern Plains — bus stops become unsafe and buses struggle to start. In January 2024, Denver was among the major cities that canceled classes during a blast of dangerously cold air. There is no single statewide temperature rule; districts typically weigh wind chill, not just the thermometer. Our formula adds 5 points when the overnight low drops below −10 °C, so a brutally cold, snow-free morning can still push your score up.
How many inches of snow cancels school in Colorado?
Colorado is two states wearing one name. The mountain districts are the most snow-equipped in the country — they run on snow that would close almost anywhere else, and closures there usually need a genuinely exceptional storm or avalanche-controlled highways. The Front Range is different: Denver-metro districts close on upslope storms dropping around 4–7 inches of wet spring snow, and wind on the open plains turns modest totals into blizzard closures east of the metro. Dry powder that brushes off a windshield and wet March cement are different substances — Colorado’s inches are the least comparable in America.
Will there be a snow day in Colorado tomorrow?
It is the question this page answers every day. Put your Colorado ZIP in the calculator above for tonight's live score at your exact location — or go straight to tomorrow's snow day chances for the morning-by-morning view, today's snow day status if snow is already falling, and our school closing predictor for district-style closing calls. The full snow day predictor breaks down every factor behind your score.
Checking another state? The same live forecast powers our Missouri snow day calculator, Minnesota snow day calculator and Wisconsin snow day calculator — or start from the main snow day calculator for any US ZIP or Canadian postal code.
Frequently asked questions
Why is March Denver's snowiest month, not January?
Spring air holds more moisture, and March upslope storms tap into it. March averages about 29 cm in Denver on the long record — more than any other month — and March delivered the city's second-biggest storm ever, about 81 cm in 2003.
Why did Douglas County close when Denver stayed open?
Elevation. Much of Douglas County sits on the Palmer Divide, up to about 2,400 metres, against Denver's 1,610 metres, and upslope flow enhances snow there — Castle Rock can be buried while Denver gets a fraction of it. Each district decides separately.
When are Colorado school closings usually announced?
Early. Denver Public Schools aims to decide by about 5 AM, and most metro districts announce early by text, email, app and local news closing lists. For a well-forecast storm, some announce the evening before.
Do schools in ski towns like Breckenridge close for snow?
Rarely. Breckenridge averages about 4.7 metres of snow a season, so roads, buses and families are built around it. A storm that closes Denver-metro districts is usually a normal school day there, though extreme wind or cold can still force a closure.
Can Colorado schools close for cold with no snow at all?
Yes. Arctic outbreaks can push wind chills to dangerous levels, especially on the windy plains, making bus stops unsafe and buses hard to start. Denver canceled classes in the January 2024 cold blast. There is no statewide threshold — each district weighs the wind chill itself.
Will there be a snow day in Colorado tomorrow?
Colorado’s answer is elevation: the metro, the foothills and the high country can have three different mornings. Enter your ZIP code above tonight, and check again in the morning — upslope storms strengthen and die faster than almost any other pattern. Districts typically announce between 5 and 6 AM.
How many inches of snow does Colorado need for a snow day?
There is no official number. Front Range districts tip around 4–7 inches (10–18 cm) of overnight snow, especially wet spring snow; mountain districts need far more; and plains wind can close schools on totals the mountains would call a dusting.
How accurate is the Colorado snow day calculator?
The score is built from the live hourly forecast for your ZIP code plus the factors districts actually weigh — timing, ice risk, wind and cold. It is sharpest 12–24 hours out, and Colorado’s upslope storms are its honest challenge: they can double or halve overnight. Our accuracy page explains how the score is checked against real outcomes.